This invention relates generally to locking devices that operate like a combination lock--without the insertion of a separable key; more specifically, it relates to an apparatus in which certain permanently contained levers are moved to predetermined positions in order to open the apparatus. A distinguishing characteristic of the preferred embodiment of the apparatus is that is is always biased to a locking position and can never be accidentally left in an unlocked condition.
There are many situations in which there is a desire to have some structure secured against movement (i.e., locked) without requiring that there be some type of key that is insertable into a recess for the purpose of effecting release of the locking device. As a class, such keyless devices may generally be found in the following U.S. patents: U.S. Pat. No. 612,335 to Haggstrom entitled "Permutation Lock"; U.S. Pat. No. 1,556,687 to Haynes entitled "Lock"; U.S. Pat. No. 3,087,765 to Chapman entitled "Medicine Cabinet Latch"; U.S. Pat. No. 4,176,533 to Nordendale entitled "Wall Safe Lock"; and U.S. Pat. No. 4,524,592 to Saitoh entitled "Combination Lock." Of these patents, perhaps the closest ones to the concept to be described herein are U.S. Pat. Nos. 3,087,765 to Chapman and 4,524,592 to Saitoh. The Chapman latch is appealing because it offers the possibility of permitting ready access to the interior of a container like a medicine cabinet to all persons who are informed of the correct combination, while denying access to children or other persons who should properly be excluded from the cabinet. And there are many "real life" situations that are analogous to the medicine cabinet example. And even if common sense did not dictate that certain persons be excluded from a certain thing or secured area, we now find that there are legislative bodies that have decided to pass laws that impose criminal penalities upon those who fail to keep weapons such as firemans out of reach of children. The State of Florida is one example of a state that has recently chosen to establish criminal penalties for adults who leave firearms where they can easily be picked up and used (or misused) by minors.
While a resident of Florida would now have even more interest in keeping a firearm secured against access by unauthorized persons, those people who have a legitimate need or desire to keep firearms readily available would probably not immediately jump at the opportunity to use a traditional lock and key for controlling access to a gun case or the like. For example, if a homeowner has been frequently subjected to attempts at nighttime burglary, he or she probably would not want to have to search in the middle of the night for a key in order to open a case where a gun is being stored. Similarly, the manager of a service station may want to secure the keys to a wrecker or service truck in such a way that employees can easily obtain access to the vehicle keys without requiring that they first find the only key to a security box. By using a combination-type lock, employees need only be informed of the combination in order to have access to whatever things are secured in a locked box.
While the idea of providing a keyless or combination lock is not new, most of the previously known combination locks have been characterized by requiring the proper positioning or alignment of certain rings, dials, or levers, all of which have indicia on them. To be able to open such locks, a person must first be able to see the indicia--which automatically eliminates a considerable number of blind and sight-impaired people. And even if a person can see well in normal daylight, there might not be enough ambient light in a dark room to permit a person to read the numerals on a dial or see the letters on a pad of push-buttons. There has remained a need, therefore, for a device that is capable of being easily opened by a blind person, or a person who wants to open a secure container without the benefit of seeing indicia on one or more dials, etc. It is an object of this invention to provide such a locking apparatus.
Another object is to provide a locking apparatus of the combination type in which the combination may be changed by any person who has the ability to gain access to the interior of the apparatus, and who the minimal mechanical ability to temporarily remove a couple of fasteners and relocate one or more levers.
A further object is to provide a lock that is easy to open but which is compact, economical and versatile enough to be attached to a variety of containers including boxes, trunks, cabinets, cases, trays, cabinets, and drawers, to provide dependable security for the contents of such containers. This is true whether the container is expected to routinely hold medicines or toxic cleaning agents, firearms or jewelry, vehicle keys or private correspondence and financial records, etc.
These and other objects will be apparent from a reading of the specification and the attached claims, with appropriate reference to the attached figures of the drawing.